A preliminary crown biomass table for even-aged Picea abies stands in Switzerland

• Published in: Forestry (London) Vol. 70; no. 2; pp. 103 - 112
• Main Authors: Usoltsev, V. A., Hoffmann, C. W.
• Format: Journal Article
• Language: English
• Published: 01-01-1997
• ISSN: 0015-752X; 1464-3626
• DOI: 10.1093/forestry/70.2.113-a

The assessment of biomass and biomass changes due to environmental influences requires not only stem or merchantable mass, but also branches and needles. They have been of relatively lit-tle importance to forest managers to date, but their inclusion in models can make the resulting predictions more precise. A hybrid method is described to derive regressions for site quality, needle and branch biomass for individual Picea abies trees. By using Swiss stand table data on tree density distributions, a traditional yield table for branch and needle biomass is computed, and from these, regressions are derived which use only age and site quality as independent vari-ables. Three tables for typical site qualities are given. The tabulated regressions include pseudo-probability values, coefficients of determination and estimated standard error for the overall models.
These biomass fractions comprise a varying fraction of the tree, being important at low ages and much less so at later ages.